Oregon Attorney General Ellen Rosenblum says in a new legal filing that U.S. District Judge Michael McShane should reject the National Organization for Marriage's "unreasonably delayed" attempt to intervene in the gay marriage lawsuit.

She also said in a legal brief filed Friday that NOM hasn't raised any new issues in the case and that only the attorney general can represent the state's interests.

NOM filed a motion to intervene in the case less than 48 hours before McShane held oral arguments on April 23 on why the parties in the case believe that Oregon's prohibition on same-sex marriage violates federal constitutional protections.

At the time, John Eastman, NOM's chairman and attorney, said his group wanted to intervene to to represent voters who approved the 2004 state constitutional amendment limiting marriage to one man and one woman. He said the intervention request came as late as it did because the extent of Rosenblum's legal reasoning wasn't made clear until mid-March and it took his group time to round up Oregon NOM members who could serve as parties in the case.

Rosenblum scoffed at that reasoning, noting that she held a Feb. 20 press conference announcing that she would not defend Oregon's ban on gay marriage. She noted that NOM also knew of her decision since it issued a press release condemning her.

Delay would not be a particular factor here if NOM had acted with reasonable speed when it knew the Attorney General’s position, in February. It chose not to, and should not be rewarded for its delay by obtaining its own separate briefing schedule, its own hearing on its own arguments, and a later decision on the plaintiffs’ rights.

The plaintiffs in the case, who include four gay and lesbian couples seeking the right to marry, also opposed NOM's request to intervene. Their brief said that the attorney general's office had signaled in legal filings as early as October of 2013 that Rosenblum's office would not be mounting a strong legal defense of the law.

Rosenblum also said that "NOM and its members have no right to substitute their voice or their judgment for that of the Attorney General simply because they disagree with the chief law officer’s conclusions."

She further said that NOM "fails to identify any argument that has not already been presented to this Court by the defendants. Instead, what it would appear to offer this Court is the same arguments identified and presented by the state defendants without the context of how those arguments fail when considered in the full context of Oregon law."

The attorney general and the plaintiffs argued in their briefs that the U.S. Supreme Court's Hollingsworth decision last year out of California strictly limited which parties had standing in a legal dispute over that state's marriage law.

They also argued that NOM would not have legal standing to appeal any decision by McShane, which the marriage group said is a major purpose for its intervention.

NOM has until Friday to reply to the latest briefs from Rosenblum and the plaintiffs. McShane has scheduled May 14 oral arguments on NOM's motion to intervene.